US 2010/0302822 A1 · Flyback Power converters

Abstract

Designs of flyback power converters are described. According to one aspect of the designs, a power converter includes a primary side including a primary winding of a transformer coupled to an input voltage and a primary switch for switching on or off the primary winding, a secondary side including a secondary winding of the transformer for generating an output voltage, and a loop controller configured to sample a feedback voltage representative of the output voltage, generate a gate signal with a fixed falling edge and an adjustable rising edge to drive the primary switch, and adjust a duty cycle of the gate signal by adjusting the rising edge of the gate signal until the feedback voltage converges to a reference voltage.

Claims11

Dependent claims

A power converter, comprising:

a primary side comprising a primary winding of a transformer coupled to an input voltage and a primary switch for switching on or off the primary winding;
a secondary side comprising a secondary winding of the transformer for generating an output voltage;
and
a loop controller configured for sampling a feedback voltage representative of the output voltage, generating a gate signal with a fixed falling edge and an adjustable rising edge to drive the primary switch, and adjusting a duty cycle of the gate signal by adjusting the rising edge of the gate signal until the feedback voltage converges to a reference voltage.

1 more element

A controller for a power converter, comprising:

a voltage feedback circuit for providing a feedback voltage representative of an output voltage of the power converter;
an oscillator circuit for generating an asymmetric saw-tooth signal having a slow slope edge and a fast steep edge and a clock signal synchronous with the asymmetric saw-tooth signal;
an error amplifier configured for amplifying a difference between a reference voltage and the feedback voltage to get an error signal;
a PWM comparator configured for comparing the error signal with the saw-tooth signal to get a PWM signal having an adjustable rising edge;
and
a control logic circuit configured for generating a gate signal having a fixed falling edge determined by a falling edge of the clock signal and an adjustable rising edge determined by the rising edge of the PWM signal.

3 more elements

Dependencies are inferred from the claim text.

Flyback Power converters

Life of this patent

Flyback Power converters

Life of this patent

Abstract

Claims11